Get Prepped! Preheat your oven to 350°F (175°C). Line a 10x15 inch jelly roll pan with parchment paper, leaving some overhang on the sides.
Whisk the Dry Ingredients. In a medium bowl, whisk together the almond flour, coconut flour, baking powder, xanthan gum, sea salt, granulated sweetener blend, and pumpkin pie spice. Make sure everything is well combined.
Mix the Wet Ingredients. In a separate large bowl, whisk together the eggs, pumpkin puree, and vanilla extract until smooth.
Combine Wet and Dry. Add the dry ingredients to the wet ingredients and mix with a spatula or spoon until just combined. Don't overmix! The batter will be thick, but spreadable.
Spread the Batter. Pour the batter onto your prepared pan. Use an offset spatula to spread it evenly right to the edges. Try to make it as uniform in thickness as possible for even baking.
Bake! Pop the pan in the preheated oven and bake for 12-15 minutes, or until the cake is set, springs back when lightly touched, and the edges are lightly golden. Don't overbake, or it will crack when you roll it!
Prepare for Rolling. While the cake is baking, lay out a clean kitchen towel on your counter or a cooling rack. Dust it lightly with a little extra powdered keto sweetener or coconut flour. This helps prevent sticking.
Roll It Up! As soon as the cake comes out of the oven, carefully invert the hot cake onto the prepared towel. Gently peel off the parchment paper. Starting from a short end, tightly roll the cake up in the towel. Don't worry if you hear a tiny crackle – it's usually okay! Place the rolled cake, seam-side down, on a cooling rack and let it cool completely. This rolling-while-warm step is crucial for training the cake to hold its shape!
Make the Filling. While the cake cools, make the filling. In a medium bowl, beat together the softened butter and softened cream cheese until light and fluffy using an electric mixer. Gradually add the powdered sweetener and vanilla extract. Beat until smooth and creamy. Scrape down the sides as needed.
Fill 'Er Up! Once the cake is completely cool (this is important!), gently unroll it. Spread the cream cheese filling evenly over the inside surface of the cake, leaving a small border (about 1/2 inch) around the edges. This prevents the filling from squeezing out the ends when you re-roll.
Re-Roll. Starting from the same short end you started with before, carefully re-roll the cake back up, without the towel this time! Use the towel or parchment paper you baked it on underneath to help you lift and guide if needed.
Chill and Enjoy! Wrap the finished roll tightly in plastic wrap, then place it in the refrigerator for at least 1-2 hours to allow the filling to set and the cake to firm up. When ready to serve, you can dust the top with a little more powdered sweetener if desired. Slice with a sharp knife and get ready for deliciousness!